WASHINGTON — There’s a stampede to share a stage with Bernie Sanders. Once again, the socialist senator has introduced a bill to bring Canadian-style, single-payer health care to the United States. Only this time, he’s surrounded by the stars of the Democratic party.

A raucous rally to introduce Sanders’ latest medicare-for-all bill underscored how the idea of universal public health care has swiftly moved from the no-hope fringes of U.S. politics to becoming mainstream within one of the country’s two major parties.

Sanders, whose stronger-than-expected presidential bid helped prod the party to the left, quipped in a letter to supporters before the launch event: “The last time I introduced this bill, it lacked a single co-sponsor.”

Not this time. On Wednesday, there were dozens of television cameras, hundreds of spectators and a lineup outside the event where potential presidential aspirants like Kamala Harris, Cory Booker, Elizabeth Warren, and Kirsten Gillibrand declared themselves among the bill’s more than 15 co-sponsors.

A Canadian doctor spoke at the event.

Danielle Martin described how her grandfather’s family was essentially bankrupted by medical bills after his heart attack and she called that inconceivable to generations of younger Canadians.

The Toronto physician pulled out her medicare card and said universal health access is now a top element of the national identity.

“Even more than ice hockey,” she said, drawing laughs.

“Single-payer health care is a symbol to us of what it means to be Canadian.”

One of the rising stars of the Democratic party said he felt shame at what he heard. Other speakers at the rally had shared horror stories about painful, life-and-death financial decisions, including undergoing surgery without anaesthesia because it cost too much.

“It is embarrassing to me,” said Booker, a New Jersey senator.

“I love my northern neighbour but it is embarrassing to me to have a Canadian stand here in the capital of the United States of America and talk about a system that takes care of their children better than we take care of our children.”

The United States has taken a decidedly different route from Canada, whose single-payer experiment began in Saskatchewan with a heated debate and doctors’ strike in 1962.

The U.S. has a patchwork system that’s mostly private, partly public and covers the vast majority of Americans. When Barack Obama took office, about 84 per cent of Americans had health coverage; the number rose to about 89 per cent under his reform; now the parties are debating next steps.

Some Republicans are still working on bills to pare back Obamacare. Some Democrats want to focus their fight on saving what exists. But others, like Sanders, want to expand the battle to new terrain: single-payer.

Republicans are preparing for that fight.

A GOP senator raised the issue at a news conference, without being asked. Wyoming Sen. John Barrasso pointed out that Sanders’ home state of Vermont made a serious push for single-payer a few years ago — and dropped it because it would require a big tax increase.

“It seems that this complete government takeover of health care is becoming the litmus test for the liberal left,” Barrasso said.

“While Bernie Sanders’ slogan may be very popular, it’s really the nuts-and-bolts and the details that matter the most. What’s it going to cost the American people?”

Polling on the issue makes it obvious why Republicans focus on the fiscal effects.

A Kaiser Foundation survey finds strong U.S. support for single-payer when you call it “Medicare For All” — at 57 per cent. To Americans’ ears, Medicare is the popular public program that provides health coverage for seniors and it’s the closest thing the U.S. has to single-payer.

But mention taxes, and the support plummets. When respondents were told taxes would go up, Kaiser found that opposition grew from 40 per cent to more than 60 per cent.

A single-payer system would require tax revenue.

A researcher at the University of Massachusetts has concluded that a U.S. single-payer system would require a six-per-cent tax hike on top-earning households, a three-per-cent hike on lower-earning households, and smaller taxes for different types of stock trades ranging from 0.1 per cent to 0.5 per cent.

The slog ahead remains huge.

With support from barely half the Democratic caucus, single-payer still only wins the votes of about one-quarter of the Congress. Meanwhile, Democrats running in tough races in 2018 are less likely to get behind the idea.

“I support fixing what we’ve got,” said Sen. Jon Tester, who faces re-election in Montana.

“I think that’s more likely to happen.”

Another Democrat proposed a more flexible fix, via the magic of federalism.

Ron Wyden of Oregon says he inserted a clause in Obamacare a few years ago that allows states to opt out — provided they expand coverage. He suggests his state, California, and Washington could start their own single-payer system.